n absorbed in the examination of
that now well-known machine, which was then, to me at least, a
novelty,--invented, if I remember right, by Dubois-Reymond, so
distinguished by his researches into the mysteries of organic
electricity. It is a wooden cylinder fixed against the edge of a table;
on the table two vessels filled with salt and water are so placed that,
as you close your hands on the cylinder, the forefinger of each hand
can drop into the water; each of the vessels has a metallic plate,
and communicates by wires with a galvanometer with its needle. Now the
theory is, that if you clutch the cylinder firmly with the right hand,
leaving the left perfectly passive, the needle in the galvanometer will
move from west to south; if, in like manner, you exert the left arm,
leaving the right arm passive, the needle will deflect from west to
north. Hence, it is argued that the electric current is induced through
the agency of the nervous system, and that, as human Will produces the
muscular contraction requisite, so is it human Will that causes
the deflection of the needle. I imagine that if this theory were
substantiated by experiment, the discovery might lead to some sublime
and unconjectured secrets of science. For human Will, thus actively
effective on the electric current, and all matter, animate or inanimate,
having more or less of electricity, a vast field became opened to
conjecture. By what series of patient experimental deduction might not
science arrive at the solution of problems which the Newtonian law of
gravitation does not suffice to solve; and--But here I halt. At the
date which my story has reached, my mind never lost itself long in the
Cloudland of Guess.

I was dissatisfied with my experiment. The needle stirred, indeed,
but erratically, and not in directions which, according to the theory,
should correspond to my movement. I was about to dismiss the trial with
some uncharitable contempt of the foreign philosopher's dogmas, when
I heard a loud ring at my street-door. While I paused to conjecture
whether my servant was yet up to attend to the door, and which of my
patients was the most likely to summon me at so unseasonable an hour,
a shadow darkened my window. I looked up, and to my astonishment beheld
the brilliant face of Mr. Margrave. The sash to the door was already
partially opened; he raised it higher, and walked into the room. "Was it
you who rang at the street-door, and at this hour?" said I.